Explanation of Header Pixel in GIMP created C Header File of an XPM image

Question

In GIMP, you\'re able to save an image as a C header file. I did so with an XPM file, which looks like the image below:

Answer 1

Each pixel is represented by 3 bytes. These pixels are defined as a character array, named header_data.

The problem is that not every byte is a printable character that could exist in that header file.

This is solved by only using the printable characters 33 through 97. That gives 6 bits of information, so every four characters will give 24 bits, which can represent all permutations of 3 bytes.